Patent GB-571157-A (GB)
Title: Manufacture of salts of nitro sulphonic acids
IPC: C07C309/03
Filed: 1944-02-12
Abstract: Salts of b -nitro-alkane sulphonic acids are prepared by a process comprising interacting a D a -nitro-olefine of the formula CRR1=CR11 NO2, wherein R, R1 and R11 may be hydrogen or hydrocarbon radicals and either R or R1 with R11 may together form part of a cycloaliphatic ring, with a water-soluble inorganic sulphite or bisulphite.  The nitro olefines which may be used include nitro-ethylene, 1-nitropropene, 2 - nitro - propene, 2 - nitro - 2 - butene, 1 - nitro - 2 - methyl - 1 - propene, 1 - nitro-2-phenyl-ethylene, 1-nitrocyclohexene, 1-nitro-1-methyl-2 - phenylethylene, and 2 - nitro - 4 - methyl - 2 - pentene; there may also be used substances which under the conditions of the reaction give rise to D a -nitro-olefines, for example, esters of the alcohols which may be conceived as formed by the hydration of these olefines, viz. alcohols of the formula HO.CRR1-CHR11NO2, wherein R, R1, R11 have the significance given above. The esters may be those of organic acids such as acetic acid, or of mineral acids such as hydrochloric or nitric acid.  Thus, there may be used b -nitro-ethyl nitrate or 2-nitropropanol acetate. The water-soluble inorganic sulphites or bisulphites used include sodium, potassium and ammonium sulphites or bisulphites and calcium bisulphite.  The reaction is conveniently carried out in an aqueous medium which may be water or a mixture of water and a water-miscible solvent such as methanol or dioxan.  The b -nitro alkane sulphonic acid salts are isolated by evaporation.  They may be reduced by conventional methods to give the corresponding b -amino alkane sulphonic acid salts, from which the b -amino alkane sulphonic acids may be obtained on acidification.  In examples: (1) nitroethylene is reacted with an aqueous solution of sodium bisulphite to yield the sodium salt of b -nitroethane sulphonic acid which on reduction with hydrogen in the presence of a Raney nickel catalyst yields the corresponding amino salt from which taurine is obtained on treatment with hydrochloric acid; (2) 1-nitropropene and sodium bisulphite give sodium 1-nitropropane-2-sulphonate from which the p-toluidine salt is obtained by treatment with a solution of toluidine hydrochloride; (3) 1-nitro-1-methyl-2-phenylethylene and sodium bisulphite give sodium 1 - nitro - 1 - methyl - 2 - phenylethane - 2 - sulphonate; (4) 2-nitropropene and sodium bisulphite give sodium 2-nitro-propane-1-sulphonate which on reduction yields sodium 2-amino-propane-1-sulphonate as in (1) above; (5) 2-nitro-2-butene and sodium bisulphite give sodium 2-nitrobutene-3-sulphonate from which sodium 2-aminobutane-3-sulphonate and the free acid are obtained as above; (6) b -nitroethyl nitrate and sodium bisulphite react to yield sodium b -nitroethane sulphonate; (7) 2-nitro-propanol acetate and sodium bisulphite yield sodium 2-nitro-propane-1-sulphonate from which sodium 2-amino-propane-1-sulphonate and the free acid are obtained as above; (8) 1-nitro-2-methyl-1-propene and sodium bisulphite yield sodium 1-nitro-2-methyl-propane-1-sulphonate from which sodium 2-amino-propane-1-sulphonate and the free acid may be obtained as above; (9) 2-nitro-4-methyl-2-pentene and sodium bisulphite yield sodium 2-nitro-4-methyl - 2 - pentane sulphonate from which sodium 2-amino-4-methyl-2-pentane sulphonate and the free acid are obtained as above; (10) 1-nitrocyclohexene and sodium bisulphite yield sodium 1-nitrocyclohexane-2-sulphonate; (11) 1-nitro-propene and sodium sulphite heptahydrate yield disodium 1-aci-nitropropane-2-sulphonic acid from which disodium 1-amino-propane-2-sulphonic acid and the free acid are obtained as above; (12) 1 - nitro - 2 - phenyl - ethylene and sodium bisulphite yield sodium 1 - nitro - 2 - phenylethane - 2 - sulphonate from which sodium 1 - amino - 2 - phenylethane sulphonate and the free acid are obtained as above. 2-Nitro-4-methyl-2-pentene is obtained by condensation of isobutyraldehyde with nitroethane in the presence of diethylamine.